When reproducing color with a rendering device, e.g., a display or a printer, the rendering device has inherent limitations in terms of the colors it can produce and a unique gamut, i.e., a unique set of colors that can be reproduced by the rendering device. Accordingly, when a given image is specified with input color separation data (e.g., CMYK data configured for an offset press) not directly compatible with the rendering device's gamut (e.g., requiring CMYK data for a particular type of printer), it must be converted using a color data conversion subsystem (e.g., a set of B2A tags incorporating respective color lookup tables). This color data conversion subsystem ideally will produce output color separation data causing the best reproduction of the image's colors, best portraying hue, color differences, and a number of other aspects of the image's colors.